2018-12-03 00:54:25

by Sam Bobroff

[permalink] [raw]
Subject: [PATCH v2 0/2] Two AST driver fixes

Hello,

Here are two (attempted) fixes for the AST DRM driver. The issues they fix are
both seen when the ast driver is unloaded (tested on Power9, although it looks
like the second one is architecture independent).

I'm fairly confident about the first fix, as it looks pretty straight forward.

The second seems reasonable, but I don't know this area of the kernel very well.

Cheers,
Sam.

Patch set changelog follows:

Patch set v2:
Patch 1/2: drm/ast: Fix incorrect free on ioregs
Patch 2/2: drm/ast: Fix connector leak during driver unload
* Changed to use drm_crtc_force_disable_all().

Patch set v1:
Patch 1/2: drm/ast: Fix incorrect free on ioregs
Patch 2/2: drm/ast: Fix connector leak during driver unload

Sam Bobroff (2):
drm/ast: Fix incorrect free on ioregs
drm/ast: Fix connector leak during driver unload

drivers/gpu/drm/ast/ast_fb.c | 1 +
drivers/gpu/drm/ast/ast_main.c | 3 ++-
2 files changed, 3 insertions(+), 1 deletion(-)

--
2.19.0.2.gcad72f5712



2018-12-03 00:54:28

by Sam Bobroff

[permalink] [raw]
Subject: [PATCH v2 2/2] drm/ast: Fix connector leak during driver unload

When unloading the ast driver, a warning message is printed by
drm_mode_config_cleanup() because a reference is still held to one of
the drm_connector structs.

Correct this by calling drm_crtc_force_disable_all() in
ast_fbdev_destroy().

Signed-off-by: Sam Bobroff <[email protected]>
---
v2 * Changed to use drm_crtc_force_disable_all().

drivers/gpu/drm/ast/ast_fb.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
index 0cd827e11fa2..de26df0c6044 100644
--- a/drivers/gpu/drm/ast/ast_fb.c
+++ b/drivers/gpu/drm/ast/ast_fb.c
@@ -263,6 +263,7 @@ static void ast_fbdev_destroy(struct drm_device *dev,
{
struct ast_framebuffer *afb = &afbdev->afb;

+ drm_crtc_force_disable_all(dev);
drm_fb_helper_unregister_fbi(&afbdev->helper);

if (afb->obj) {
--
2.19.0.2.gcad72f5712


2018-12-03 00:56:41

by Sam Bobroff

[permalink] [raw]
Subject: [PATCH v2 1/2] drm/ast: Fix incorrect free on ioregs

If the platform has no IO space, ioregs is placed next to the already
allocated regs. In this case, it should not be separately freed.

This prevents a kernel warning from __vunmap "Trying to vfree()
nonexistent vm area" when unloading the driver.

Fixes: 0dd68309b9c5 ("drm/ast: Try to use MMIO registers when PIO isn't supported")

Signed-off-by: Sam Bobroff <[email protected]>
---
drivers/gpu/drm/ast/ast_main.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index dac355812adc..373700c05a00 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -583,7 +583,8 @@ void ast_driver_unload(struct drm_device *dev)
drm_mode_config_cleanup(dev);

ast_mm_fini(ast);
- pci_iounmap(dev->pdev, ast->ioregs);
+ if (ast->ioregs != ast->regs + AST_IO_MM_OFFSET)
+ pci_iounmap(dev->pdev, ast->ioregs);
pci_iounmap(dev->pdev, ast->regs);
kfree(ast);
}
--
2.19.0.2.gcad72f5712


2018-12-04 12:14:46

by Daniel Vetter

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] drm/ast: Fix connector leak during driver unload

On Mon, Dec 03, 2018 at 11:53:21AM +1100, Sam Bobroff wrote:
> When unloading the ast driver, a warning message is printed by
> drm_mode_config_cleanup() because a reference is still held to one of
> the drm_connector structs.
>
> Correct this by calling drm_crtc_force_disable_all() in
> ast_fbdev_destroy().
>
> Signed-off-by: Sam Bobroff <[email protected]>
> ---
> v2 * Changed to use drm_crtc_force_disable_all().

Reviewed-by: Daniel Vetter <[email protected]>

>
> drivers/gpu/drm/ast/ast_fb.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
> index 0cd827e11fa2..de26df0c6044 100644
> --- a/drivers/gpu/drm/ast/ast_fb.c
> +++ b/drivers/gpu/drm/ast/ast_fb.c
> @@ -263,6 +263,7 @@ static void ast_fbdev_destroy(struct drm_device *dev,
> {
> struct ast_framebuffer *afb = &afbdev->afb;
>
> + drm_crtc_force_disable_all(dev);
> drm_fb_helper_unregister_fbi(&afbdev->helper);
>
> if (afb->obj) {
> --
> 2.19.0.2.gcad72f5712
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch